GIT-INDEX-PACK(1)		  Git Manual		     GIT-INDEX-PACK(1)

NAME
       git-index-pack - Build pack index file for an existing packed archive

SYNOPSIS
       git index-pack [-v] [-o <index-file>] [--[no-]rev-index] <pack-file>
       git index-pack --stdin [--fix-thin] [--keep] [-v] [-o <index-file>]
			 [--[no-]rev-index] [<pack-file>]


DESCRIPTION
       Reads a packed archive (.pack) from the specified file, builds a pack
       index file (.idx) for it, and optionally writes a reverse-index (.rev)
       for the specified pack. The packed archive, together with the pack
       index, can then be placed in the objects/pack/ directory of a Git
       repository.

OPTIONS
       -v
	   Be verbose about what is going on, including progress status.

       -o <index-file>
	   Write the generated pack index into the specified file. Without
	   this option the name of pack index file is constructed from the
	   name of packed archive file by replacing .pack with .idx (and the
	   program fails if the name of packed archive does not end with
	   .pack).

       --[no-]rev-index
	   When this flag is provided, generate a reverse index (a .rev file)
	   corresponding to the given pack. If --verify is given, ensure that
	   the existing reverse index is correct. Takes precedence over
	   pack.writeReverseIndex.

       --stdin
	   When this flag is provided, the pack is read from stdin instead and
	   a copy is then written to <pack-file>. If <pack-file> is not
	   specified, the pack is written to objects/pack/ directory of the
	   current Git repository with a default name determined from the pack
	   content. If <pack-file> is not specified consider using --keep to
	   prevent a race condition between this process and git repack.

       --fix-thin
	   Fix a "thin" pack produced by git pack-objects --thin (see git-
	   pack-objects(1) for details) by adding the excluded objects the
	   deltified objects are based on to the pack. This option only makes
	   sense in conjunction with --stdin.

       --keep
	   Before moving the index into its final destination create an empty
	   .keep file for the associated pack file. This option is usually
	   necessary with --stdin to prevent a simultaneous git repack process
	   from deleting the newly constructed pack and index before refs can
	   be updated to use objects contained in the pack.

       --keep=<msg>
	   Like --keep, create a .keep file before moving the index into its
	   final destination. However, instead of creating an empty file place
	   <msg> followed by an LF into the .keep file. The <msg> message can
	   later be searched for within all .keep files to locate any which
	   have outlived their usefulness.

       --index-version=<version>[,<offset>]
	   This is intended to be used by the test suite only. It allows to
	   force the version for the generated pack index, and to force 64-bit
	   index entries on objects located above the given offset.

       --strict[=<msg-id>=<severity>...]
	   Die, if the pack contains broken objects or links. An optional
	   comma-separated list of <msg-id>=<severity> can be passed to change
	   the severity of some possible issues, e.g.,
	   --strict="missingEmail=ignore,badTagName=error". See the entry for
	   the fsck.<msg-id> configuration options in git-fsck(1) for more
	   information on the possible values of <msg-id> and <severity>.

       --progress-title
	   For internal use only.

	   Set the title of the progress bar. The title is "Receiving objects"
	   by default and "Indexing objects" when --stdin is specified.

       --check-self-contained-and-connected
	   Die if the pack contains broken links. For internal use only.

       --fsck-objects[=<msg-id>=<severity>...]
	   Die if the pack contains broken objects, but unlike --strict, don’t
	   choke on broken links. If the pack contains a tree pointing to a
	   .gitmodules blob that does not exist, prints the hash of that blob
	   (for the caller to check) after the hash that goes into the name of
	   the pack/idx file (see "Notes").

	   An optional comma-separated list of <msg-id>=<severity> can be
	   passed to change the severity of some possible issues, e.g.,
	   --fsck-objects="missingEmail=ignore,badTagName=ignore". See the
	   entry for the fsck.<msg-id> configuration options in git-fsck(1)
	   for more information on the possible values of <msg-id> and
	   <severity>.

       --threads=<n>
	   Specifies the number of threads to spawn when resolving deltas.
	   This requires that index-pack be compiled with pthreads otherwise
	   this option is ignored with a warning. This is meant to reduce
	   packing time on multiprocessor machines. The required amount of
	   memory for the delta search window is however multiplied by the
	   number of threads. Specifying 0 will cause Git to auto-detect the
	   number of CPU’s and use maximum 3 threads.

       --max-input-size=<size>
	   Die, if the pack is larger than <size>.

       --object-format=<hash-algorithm>
	   Specify the given object format (hash algorithm) for the pack. The
	   valid values are sha1 and (if enabled) sha256. The default is the
	   algorithm for the current repository (set by
	   extensions.objectFormat), or sha1 if no value is set or outside a
	   repository.

	   This option cannot be used with --stdin.

	   Note: At present, there is no interoperability between SHA-256
	   repositories and SHA-1 repositories.

       Historically, we warned that SHA-256 repositories may later need
       backward incompatible changes when we introduce such interoperability
       features. Today, we only expect compatible changes. Furthermore, if
       such changes prove to be necessary, it can be expected that SHA-256
       repositories created with today’s Git will be usable by future versions
       of Git without data loss.

       --promisor[=<message>]
	   Before committing the pack-index, create a .promisor file for this
	   pack. Particularly helpful when writing a promisor pack with
	   --fix-thin since the name of the pack is not final until the pack
	   has been fully written. If a <message> is provided, then that
	   content will be written to the .promisor file for future reference.
	   See partial clone[1] for more information.

	   Also, if there are objects in the given pack that references
	   non-promisor objects (in the repo), repacks those non-promisor
	   objects into a promisor pack. This avoids a situation in which a
	   repo has non-promisor objects that are accessible through promisor
	   objects.

	   Requires <pack-file> to not be specified.

NOTES
       Once the index has been created, the hash that goes into the name of
       the pack/idx file is printed to stdout. If --stdin was also used then
       this is prefixed by either "pack\t", or "keep\t" if a new .keep file
       was successfully created. This is useful to remove a .keep file used as
       a lock to prevent the race with git repack mentioned above.

GIT
       Part of the git(1) suite

NOTES
	1. partial clone
	   file:///usr/share/doc/git-doc/technical/partial-clone.html

Git 2.51.0			  2025-08-17		     GIT-INDEX-PACK(1)